In cellular telephones and other communication devices, low noise radio frequency (RF) amplifiers are typically used to amplify RF signals after reception. In such devices, linear amplification is desired to prevent signal distortion. Current drain is also a consideration, especially for mobile devices such as cellular telephones, due to the limited quantity of energy stored in the accompanying battery.
Linearity and current drain are often competing considerations. At a low bias current, an amplifier may introduce unacceptable levels of signal distortion. However, to achieve optimum linearity may require a high bias current level, thereby decreasing battery life.